Oil distillation apparatus



3)/ Hum. kf/W? 4,0%, f. fw, L7S.

A115139, 1933. A. E. PEW, JR

OIL DISTILLATION APPARATUS Original Filed April 4, 1929 Patented Aug,29, 1933 sA'r sur orties OIL DISTILLATIQN APPARATUS Arthur E. Pew, Jr.,Bryn Mawr, Pa., assigner to Sun Oil Company, Philadelphia, Pa., acorporation of New Jersey Original application April 4, 1929, Serial No.352,392. Divided and this application August 6, 1931. Serial No. 555,391

6 Claims. (Cl. 196-119) In a patent issued to me September 27, 1932, No.1,879,948, of which this application' is a division, I have set forth aprocess and apparatus for producing lubricating oil distillates ofdiiferent boiling points wherein the heat required for effectingdistillation, at least of a number of the higher boiling fractions, issupplied by the condensation of mercury Vapor generated in a pluralityof mercury boilers. The construction and arrangement whereby theseboilers are connected with a series of stills are not therein claimedand form the subject matter of this application.

The present invention may be fully disclosed by a description of thatpart of the apparatus which is in operative relation with the mercuryboilers and which is shown in diagram in the single gure oi the drawing.

In the said apparatus gasoline, kerosene, gas oil and lighterlubricating oil fractions may be distilled in an apparatus forming nopart of the present invention. For example, the lubricating oilfractions distilled in such apparatus may comprehend lubricating oilsor" 100, 200, and G at 100 F. viscosity. v

The residual oil from these preliminary distillations may be, however,so iar as concerns the present invention, oil from which any desiredfractions have been distilled. It is pumped through a line 4i) andthrough a pipe coil 4l in a heating chamber 7G. The heatinI medium inthis chamber is, preferably, mercury Vapor, but other heating media maybe substituted, particularly substances such, possibly, as diphenyloxide, benzo phenone, sulfur, or perhaps a suitableV metal alloy, as maybe found to possess those characteristics oi mercury vapor that make itespecially advantageous in the distihation of the higher boilinglubricating oils. It will be understood, therefore, that, hereinafter,when mercury boilers are referred to, the term is intended to includeboilers adapted to vaporize materials which are in a broad sense,equivalent to mercury.

In chamber the mercury vapor condenses and imparts its latent heat tothe oil flowing through coil 41. The mercury vapor is generated in amercury boiler 7l from which extends a mercury vapor pipe line 72 tochamber 70. Pipe 72 is equipped with a valve 73, by means oi which therate or" iiow oi the mercury vapor into chamber 70, and thereby thepressure and temperature of condensation within the saine and the heatto which the oil is subjected may be accurately regulated. Thistemperature oi condensation should be such that there will be acomparatively low' temperature dierence between theoil flowing throughcoil 4l and the surrounding mercury vapor as measured by the logarithmicmean temperature difference at'the inlet and the outlet of the coil. 60

Extending from chamber 70 is a mercury condensate return, whichcomprises a clean out cup 74, goose-neck 75, pipe 76 and chamber 77cornrnunicating with boiler 71. .The connections shown are adapted notonly to allow mercury condensate to return to boiler 71, but also toprovide balancing columns oi liquid mercury '(in goose-neck; to takecare of pressure diierences between boiler 71 and chamber 70.

In coil 4l the oil is heated to the 'desired temperature, say 625 F.,and suiiicient latent heat is applied to Vaporize the desired fractionwithin the coil; or, alternatively, the pressure within the coil may beso fixed as to prevent vaporzation within the coil and permit theconversion of sensible heat to latent heat in tower 42, as hereinaftermore fully described. Assuming that the vaporizatio'n is effected Withinthe coil, the oil thus heated and partly vaporized enters tower 42,rwhich may have any known eicient internal construction.' In this towerthe vapors are condensed. A small proportion of stink oil, comprisingalso' incondensible gases, escapes through line 43 and condenser 44 intoreceiving tank 45, whence the condensed stink oil may be pumped tostorage. Theniain part ofthe condensed product ows through line 46 intoa deodorizer 47, which is subjected to a high vacuum and in which theremainder or" the odor-producing gases are removed, the puriiied oilflowing through a cooler 48 into a tank 49, from which it is pumped tostorage.

The absolute pressure in tower 42 is maintained at such a point as willenable the vaporisation, in coil 4l, of the desired proportion of oil atas low a temperature as practicable. This high vacuum may be establishedand maintained through vacuum lines 50, 50.

vThe oil not vaporized in tower 42 and not escaping through line 46flows through another coil 51 inA another mercury vapor condensingchamber 80. Herein the oil is heated to a somewhat higher temperaturethan in coil 41, resulting in another partial vaporization, and flowsinto a tower 52, wherein the vaporized fraction is con-` densed: theoperation being the same as intower 42, but with the production of ahigher boiling range oil distillate.

I have shown still another mercury vapor condensing chamber 89,-ccil 51and towerv62, in

series with the fractional distillation units 70, 41, 42 and 80, 51, 52,above described, for the production of a still hie'lier boilingY rangedistillate. There may be a variable number of these units, dependent onthe neness of the cuts desired, and dependent also on the proportion ofthe distillates which it is desired to produce by the use of mercuryvapor as a heating medium ascompared with the proportion of relativelylight distillates which it is desired to obtain in the preliminarydistillation hereinbefore referred to, forming no part of the presentinvention. Other factors also will govern the design of the plant. Withthe use or a considerable number of units, the temperature elevations ineach unit will be reduced, with the resultant advantage that the oilwill be subjected to the action of the heating medium for very shortperiods of time.

Any number of boilers may be used. In the drawing is shown two boilers,"Il and 81, with mercury vapor outflow lines 72 and 82 respectively andmercury condensate return lines v76 and 86 respectively. Boiler 71 isshown as connecting with oil heater rIO and boiler 81 with oil heater89, while each boiler is connectible with oil heater through branchmercury vapor inlet pipes 720 and S26 respectively and mercurycondensate return line 78, which latter may be connected with'eitherline 76 or line 86 through one of the goose-necks 84. Mercury vaporlines 72 and 82 may be, cross-connected by means or" pipe '700. Chambers77 of the mercury condensate returns to the two boilers may becross-connected by means of pipe 110. Valves 111 are positioned in theshort pipes connecting chambers 77 with their respective boilers and avalve 112 is positioned in the cross-connecting pipe 11i). Thereby,either boiler may be connected, and the other disconnected, with all the`oil heating chambers.

The described arrangement of boilers` may be varied as desired. The useof two boilers is desirable, since it allows the generation of mercury.

vapor atpressures more nearly approximating the pressures desired in theoil heaters connected therewith and it also provides against a shut downin case one boiler should be disabled. One boiler,` however, is all thatis required, in view of the capacity to independently regulate thepressures in the several chambers'by means of the throttle valve 73, 83or 88 and the balanced mercury columns in the goose-necks '775, 84 and85.

While, as hereinbefore described, the partial vapoi-ization of the oilRowing through coils 41, 51 and 6l occurs in the coils themselves, itmay be preferable to prevent vaporization within the coils, therebypreventing any direct transfer of heat to the vapors. This can beeiected by means of pressure regulating valves 101, 102 and 103 on thepipes leading from the coils to the towers 42, 52 and '62. .When thisvariation is adopted, it is lnecessary to heat the oil'in each coil to asomewhat higher temperature than would be otherwise required to permitthe conversion o sensible heat to latent heat in the succeeding tower.Such variation of the process is also of advantage in which the oil mustbe raised therein is comparatively low. In the absence of pressurecontrol regulators, the oil in each coil will be under a vacuum butlittle lower than that in the tower, 42, 52 or 62, just beyond the coil.

It is desirable that provision be made to shut the boilers down if itbecomes necessary to shut off the flow of vmercury to the oil heaters.Should the main valves 94 on lines 72 and 82 be closed, the safetyvalves 95 would open and the mercury would rise and condense incondenser 96, flowing back, through the seals 97 into lines 76 and 86and thence into the boiler.

ItY should be understood that the present invention is not dependent onthe use of any particular type of still. The stills above describedmerely illustrate one type of still with which the mercury boilers maybe connected as herein described; but

the same connections may be made to stills of many different specificconstructions.

What I claim and desire to protect byLetters Patent is:

l. The combination with a plurality of stills arranged in series, of twomercury boilers, a mercury vapor flow pipe from one boiler communicatingwith one Vor more stills and a mercury vapor .iiow pipe from the otherboiler communicating with one or more other stills, and acrossconnecting mercury vapor flow pipe connecting the mercury vaporilow pipes from the two boilers.

. 2. The combination with a plurality of stills arranged in series, oftwo mercury boilers, pipe connections providing for a ow of mercuryvapor from one boiler to one or more stills and for the return ofcondensed mercury to the boiler, pipe connections providing for a flowof mercury vapor from the other boiler to one or more other stills andfor the return of condensed mercury to the boiler, and valve controlledcrossconnecting pipes permitting iow of mercury Vapor from either boilerto all the stills and for permitting return of condensed mercury fromall the stills to either boiler.

3. The combination with three stills arranged in series, of two mercuryboilers, a mercury vapor vflow pipe from one boiler to one end stillanda mercury vapor flow pipe from the other boiler to the other endstill, a mercury vapor flow pipe to the middle still, and means toconnect the mercury vapor liow pipe to the middle still with the mercuryvapor ilow pipe from either mercury boiler.

4. 'Ihe combination with three stills arrange in series, of two mercuryboilers, pipe connections providing for a ow of mercury vapor from oneboiler to one end still and for the return of condensed mercury to theboiler, pipe connections providing for a flow of mercury vapor from theother boiler to the other end still and for the return-of condensedmercury to the boiler, pipe connections providing for flow of mercuryvapor to the middle still and for return of condensed l mercurythererom, and means to connect the iiow pipes to and from the middlestill with the corresponding flow pipes to and from either of the otherstills.

5. The combination with a plurality of stills arranged in series, oftwo' mercury boilers, a mercury vapor iow pipe from one boilercommunieating with one still or combination of stills and aV mercuryvapor flow pipe from the other boiler communicating with another stillor combination of stills, and a cross-connecting mercury-vapor from theother boiler to another still and for the return of condensed mercury tothe boiler, and Valve-controlled cross-connecting pipes permitting flowof mercury vapor from either boiler to both stills and for permittingreturn of condensed mercury from both stills to either boiler.

ARTHUR E. PEW, JR.

